This invention relates to a test body arrangement (otherwise known as a Test Phantom) for use in checking the performance of apparatus which detects the emission of radioactive radiations from a body by means of a detector assembly positioned at a given distance from the body. The detector assembly consists, in one embodiment, of a radiation sensitive element which extends over an area in a plane. Such a detector assembly produces a planar image which may be in the form of a matrix arranged in rows and columns, suitable for subsequent computer processing. It is, of course, possible for the detector assembly to be arranged in other than a plane, for example the assembly could be arranged on a curve about a longitudinal axis of the body from which the radiations are detected. Furthermore, the detector assembly may be so mounted that it can be rotated about the body. The planar views obtained by the detector assembly at various incremental positions around the body may be reconstructed to form transaxial sectional views of that body.
One form of phantom or test body arrangement for testing the operating characteristics of a tomographic analytical apparatus is described in U.S. Pat. No. 4,055,771. The embodiments described therein disclose the use of X-ray energy absorption means which are arranged in a predetermined configuration within the body and which include a fluid bath chamber.